Container sweep for a palletizer and method

ABSTRACT

A palletizer assembly including a sweep assembly including a frame having a pair of generally parallel side members and a pair of cross members extending between respective ends of the side members, the sweep assembly also including a pair of forward stanchions that extend vertically upward from respective side members, and a pair of rearward stanchions extending vertically upward from the upstream ends of the side members, a pair of generally vertically extending slides, each having a lower end connected to a side member and an upper end, plunger assemblies including a plunger support slidably supported by a respective slide between a lowered position and a raised position, each plunger assembly including a plurality of plungers which are fixed to, and extend downwardly from, the respective plunger support, and a container shift assembly supported by the frame and including a pair of shifter slide rails extending rearwardly of the rearward plunger support, the upstream ends of the shifter slide rails being offset from the downstream ends of the slider rails.

RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §119 of co-pendingU.S. Provisional Patent Application Ser. Nos. 60/016,853; 60/017,014;and 60/016,845, all filed May 3, 1996.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention relates generally to material handling systems, andparticularly to palletizers for arranging articles on a pallet.

2. Related Prior Art

A palletizer is operable to arrange objects, such as beveragecontainers, into an organized pattern and place the objects onto apallet. It is known to provide such palletizers with a containerconveyor assembly for conducting a stream of containers. It is alsoknown to provide a palletizer with "pattern-forming" apparatus toorganize the conveyed objects into a pattern. U.S. Pat. No. 4,834,605,which issued to Jerred and which is titled "Apparatus for PalletizingLayers of Circular Containers Arranged in a Honeycomb Pattern",discloses one known apparatus for arranging a stream of generallycircular containers on a conveyor into a "voidless" arrangement ofnested, parallel rows of containers.

It is also generally known to provide a palletizer with apparatus toaccumulate a portion of the stream of conveyed containers and to movethe portion of the stream containers from the stream of conveyors onto apallet. An example of such an accumulation and sweep assembly isdisclosed in U.S. Pat. No. 5,271,709 which issued to VanderMeer et al.on Dec. 21, 1993 and which is titled "Device and Method for RepeatedlyForming a Preselected Arrangement of Conveyed Articles". It is alsoknown to provide a palletizer with a pallet dispenser, a separator sheetdispenser and a main hoist for holding a pallet in a position to receivemultiple tiers of containers and separator sheets.

SUMMARY OF THE INVENTION

The invention provides a palletizer including a container sweep assemblyoperable to repeatedly organize a stream of objects, such as containerson a conveyor, into a preselected pattern, and operable to transfer thecontainers in the preselected pattern onto a pallet. The container sweepassembly includes a container shift apparatus that removes selectedcontainers from the stream of containers, and reinserts the containersinto the stream at preselected positions to assure that the containersrepeatedly move into the desired, preselected pattern.

More particularly, the invention provides a palletizer assemblyincluding a container sweep assembly, an associated container shiftapparatus, and a main hoist. The container placement apparatus and thesweep apparatus cooperate to receive a stream of containers that havebeen organized into a voidless pattern, and to segregated the stream ofcontainers into a series of groupings or "patterns". The sweep assemblythen transfers the pattern onto a pallet in the main hoist.

The sweep apparatus operates to repeatedly transfer a predeterminedpattern of containers from a "sweep area" onto a pallet. Because of thestaggered arrangement of containers when in a voidless pattern, thestream of containers moving along the conveyor to the sweep apparatus isnot, without intervention, properly configured to provide repeatedpatterns. The container shift apparatus intervenes to rearrange selectedcontainers in the stream without interrupting the advance of the stream.The container shift apparatus properly organizes the containers byshifting a number of containers in the stream to the lead edge ofpatterns being formed to make those patterns complete. In particular,the container shift apparatus temporarily removes containers from thestream of containers, and re-inserts the temporarily removed containersinto a position occupying the lead edge of alternating patterns.

In one embodiment, the palletizer removes all but one of the containersin a row of containers from the stream, thereby leaving a singlecontainer in a row.

In another aspect of the invention, the sweep apparatus operates topermit the lines of containers to slide by the container that is leftbehind, thereby permitting the lead edge of the pattern being formed toattain the proper configuration without having to handle all of thecontainers in a row that is to be rearranged. This is accomplished byutilizing back pressure on the remaining lines of containers to pushforward past the stagger caused by the "extra" can left behind by thecontainer shifting apparatus numbered pattern. The remaining lines arepushed by back pressure and caused to slide by the "extra" can to moveinto the preselected, voidless pattern.

Among the advantages of the invention are the provision of a patternforming apparatus that has few moving parts to remove the containersfrom the stream of containers and to re-introduce the containers to thelead edge of a pattern being formed. Also, the invention provides apattern forming and sweep apparatus that does not require a number ofcontainers to be recycled through the stream of containers. Rather, aminimum containers are handled, and are handled only a single time toaccomplish the required rearrangement.

Other features and advantages of the invention will become apparent tothose skilled in the art upon review of the following detaileddescription, claims and drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a palletizer assembly embodying theinvention.

FIG. 2 is a side elevation view of the palletizer assembly shown in FIG.1.

FIG. 3 is an enlarged side elevation view of the sweep assembly which ispart of the palletizer shown in FIG. 1.

FIG. 4 is a top view of the sweep assembly illustrated in FIG. 5.

FIG. 5 is a schematic illustration of a first pattern of containersformed by the palletizer shown in FIG. 1 and prepared to be transferredonto a pallet.

FIG. 6 is a schematic view similar to FIG. 5 illustrating a secondpattern of containers.

FIG. 7 is a schematic view similar to FIG. 5 illustrating a thirdpattern of containers being formed.

FIG. 8 is a schematic view similar to FIG. 5 illustrating the thirdpattern of containers as formed by the palletizer.

FIG. 9 is a view similar to FIG. 4 illustrating the sweep assembly inthe retreated position.

FIG. 10 is a view taken generally along line 10--10 in FIG. 9.

FIG. 11 is a view taken generally along line 11--11 in FIG. 9.

FIG. 12 is a top view of the sweep assembly illustrated in FIG. 9 in theretreated and lowered position.

FIG. 13 is a side elevation view of the sweep assembly in the positionshown in FIG. 12.

FIG. 14 is a top view of the sweep assembly shown in FIG. 9 in theadvanced and lowered position.

FIG. 15 is a side elevation view of the sweep assembly shown in FIG. 14.

FIG. 16 is a top view of the sweep assembly shown in FIG. 9 in theadvanced and raised position.

FIG. 17 is a side elevational view of the sweep assembly shown in FIG.16.

FIG. 18 is a top view of the sweep assembly shown in FIG. 9 in theraised and retreat position.

FIG. 19 is a side elevation view of the sweep assembly shown in FIG. 18.

FIG. 20 is a top view of the sweep assembly shown in FIG. 9 and issimilar to FIG. 12 illustrating the sweep assembly in the retreated andlowered position.

FIG. 21 is a side elevation view of the sweep assembly shown in FIG. 20.

FIG. 22 is a top elevational view of the sweep assembly shown in FIG. 9and is similar to FIG. 14 illustrating the sweep assembly in theadvanced and lowered position.

FIG. 23 is a side elevation view of the sweep assembly shown in FIG. 22.

FIG. 24 is a top elevation view of the sweep assembly shown in FIG. 9and is similar to FIG. 18 illustrating the sweep assembly in the raisedand retreated position.

FIG. 25 is a side elevation view of the sweep assembly shown in FIG. 24.

Before one embodiment of the invention is explained in detail, it is tobe understood that the invention is not limited in its application tothe details of construction and the arrangements of components set forthin the following description or illustrated in the drawings. Theinvention is capable of other embodiments and of being practiced orbeing carried out in various ways. Also, it is to be understood that thephraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A palletizer assembly 10 embodying the invention is illustrated in thedrawings. The palletizer 10 comprises (see FIG. 1) an elevated conveyorassembly 14 for conveying a stream of articles, such as beveragecontainers C onto a pallet P. The containers are denoted in the drawingsgenerally by reference letter "C" and the pallets are denoted by theletter "P". The conveyor assembly 14 includes a conveyor drive belt 15(shown in FIG. 13) providing a moving container support surface 16 fortransporting a stream of containers C thereon. While the illustratedembodiment shows the use of a conveyor belt to transport the containersC, it will be readily understood that an air bed conveyor could also besuccessfully used as part of the conveyor assembly 14. The conveyorassembly 14 also includes (FIG. 4) a pair of generally parallel siderails 17 extending along the sides of conveyor belt 15 to retain thestream of containers C on the moving surface 16 as the containers C areconveyed.

The conveyor assembly 14 also includes (FIG. 1) a pattern former 18 forarranging the stream of containers C carried by the conveyor belt 15into a voidless pattern. As generally shown in FIG. 1, the patternformer 18 confines the stream of containers C conveyed by the conveyorbelt 15 and directs the containers C into lanes such that the containersC become aligned in staggered rows of containers.

As will be discussed in detail below, the plurality or stream ofcontainers C exiting the pattern former 18 are in a voidless arrangementconsisting of rows of containers C (a row of containers extendsperpendicular to the direction of travel of the containers) and lines ofcontainers C (a line of containers extends parallel to the direction oftravel of the containers).

The palletizer assembly 10 also includes (FIG. 1) a sweep assembly 22for repeatedly moving a discreet grouping or "pattern" of containers Cfrom the stream of containers C exiting the pattern former 18 to apallet P held by a main hoist 26 as a layer or tier of containers C. Thesweep assembly 22 moves patterns of containers C from the conveyingsurface 15 to the upper portion of the main hoist 26 and either directlyonto a pallet P or on top of a previous tier of containers C.

The palletizer assembly 10 also includes (FIGS. 12 and 13) a pluralityof selectively retractable pattern stops 28 which extend upwardlythrough the container support surface 16 adjacent the main hoist 26. Thepattern stops 28 are arranged to correspond with the profile of thestaggered lead edge of an advancing stream of containers. In theillustrated embodiment, and for reasons discussed in detail below, theillustrated pattern stops 28 are arranged to correspond with the profileof a lead edge having a row of nine containers C and a second row havingten containers C.

The pallets P are delivered to the main hoist 26 by means of a palletdispenser 30 and a pallet hoist 34 which receives a stack of pallets Pfrom the pallet dispenser 30 and which lifts individual pallets Pupwardly. The palletizer assembly 10 also includes a top frame dispenser38 for dispensing a stack of top frames, and a top frame handlerassembly 42 which moves individual top frames from the top framedispenser 38 into the main hoist 26 and on top of a completed stack ofcontainers C. The drawings denote top frames generally with referenceletter "T".

The palletizer assembly 10 also includes a separator sheet dispenser 46and a separator sheet handler assembly 50 for delivering individualseparator sheets S from the separator sheet dispenser 46 to the mainhoist 26. The separator sheets S are used to separate tiers ofcontainers C stacked on a pallet P. The palletizer assembly 10 alsoincludes a complete stack conveyor 54 which is located at the bottom ofthe main hoist 26 for receiving a completed stack comprising a palletsupporting multiple tiers of containers C with separator sheets Stherebetween and a top frame T supported by the uppermost tier ofcontainers C.

The pallet dispenser 30, pallet hoist 34 and the top frame handlerassembly 42 are further described in the following co-pendingInternational patent applications which are assigned to the assigneehereof and which are incorporated herein by reference: Ser. No.09/180,170, filed concurrently herewith and titled "Pallet and Top FrameHandler for a Palletizer and Method of Handling a Pallet and Top Framein a Palletizer" and Ser. No. 09/180,168, filed concurrently herewithand titled "Separator Sheet Handler for a Palletizer".

FIGS. 5-8 schematically illustrate the operation of palletizer assembly10 to repeatedly form groupings or patterns of containers 10. Withreference to FIG. 5, (which shows the direction of travel of thecontainers passing from right to left), the stream of containers Cexiting the pattern former 18 are arranged in nested, staggered rows ofcontainers C and lines of containers C. A row of containers C iscomprised of containers C having a common center line extendingperpendicular to the direction of travel, and a line of containers iscomprised of containers having a common center line extending parallelto the direction of travel.

In order to most efficiently load a pallet P with a portion of thecontainer stream, it is necessary to arrange the containers C into apattern having a front row, a rear or last row, and a plurality of rowstherebetween. The first and last rows of a pattern of containers C mustbe arranged so that the corners of the pallet P on which the pattern isto be supported remain unoccupied. This condition is necessary becausethe supporting surface provided by the corner of the pallet P isinsufficient to provide stable support of an additional containerlocated on the corner.

Given this condition, the second row and next to last row of containersC in a pattern may extend to the edge of the pallet P and be supportedwith sufficient stability. In this regard, FIG. 5 is illustrative. FIG.5 shows the outline of pallet P in phantom superimposed on the stream ofcontainers. The lead row (with respect to the direction of travel)includes 9 containers identified as C₁, and the last row also includes 9containers, also identified as C₁.

The pattern also has a second row of containers identified as C_(1A)including 10 containers, and a next to last row, immediately forward andadjacent the last row, including 10 containers C_(1A).

FIG. 5 thus illustrates 19 lines of containers C extending parallel tothe direction of travel and across the width of the pallet P.

Also as shown by FIG. 5, when in a voidless arrangement, the centerlines (two shown in FIG. 5) of adjacent rows of containers C arestaggered by a distance of 1/2 the diameter of the containers.Similarly, the center lines of adjacent lines of containers C are spacedapart by the distance of 1/2 the diameter of the containers.

After this first pattern of containers C shown in FIG. 5 is removed fromthe stream of containers by operation of sweep assembly 22 in a mannerdiscussed below, the remaining forwardmost row of containers continuesto advance in the direction of travel. In FIG. 5, this leading edge ofthe stream has its center line on the edge of the pallet P (which is whythis row of containers is not included in the first pattern), and would,without intervention or rearrangement, become the front row of the nextor second pattern. However, rearrangement is required because theleading edge of the advancing stream following transfer of the firstpattern comprises 10 containers C, not the required 9 containers C.

Stated otherwise, a pattern comprised of rows having a number ofcontainers totalling n and n-1 (wherein n equals the greatest number ofcontainers in any of the rows of the pattern), the first or front row ofthe pattern must total n-1 containers, and the last row of containersmust also include a total of n-1 containers.

One of the problems presented by handling containers C and solved by thepalletizer assembly 10 is the presence of the advancing row ofcontainers C following the first pattern and including a number ofcontainers totaling n, rather than the required n-1 number ofcontainers. The means by which the palletizer assembly 10 rearranges thestream of containers C to provide a row having the requisite n-1containers, i.e., 9 containers in the illustrated embodiment, isexplained generally below. This process is illustrated in FIGS. 5-8 andwill be later explained in detail.

The sweep assembly 22 reorganizes selected rows of containers in thestream of containers by temporarily removing a predetermined number ofcontainers, namely n-1 containers, from a row including n containers,and reinserting the "picked" or temporarily removed containers into thestream as a row of n-1 containers that is used as a front row ofcontainers for a pattern. This rearrangement process is accomplished bylifting the "picked" containers C from the stream, shifting eachcontainer C from the original line occupied by the picked container adistance equal to 1/2 container diameter to the next adjacent line ofcontainers, and reinserting the picked containers into the stream.

This "picking" and "shifting" process removes n-1 containers from a roworiginally including n containers, i.e., removes 9 of 10 containers inthe illustrated example. Accordingly, a single container C remains asthe only container in a row at the lead edge of an advancing stream ofcontainers. This single can is followed by a row which includes n-1containers and which, therefore, is suitable as a front row for apattern.

As is also described with particularity below, the sweep assembly 22affords passage of the advancing stream of containers past the singlecontainer C left by the "picking" and "shifting" steps, such that a rowcomprising n-1 containers C advances to the front row of the secondpattern formed by the sweep apparatus 22, and subsequently transferredinto the main hoist 26. This "slide by" step occurs repeatedly in theformation of each of the second, fourth, sixth and subsequent evenpatterns formed by the palletizer assembly 10. Similarly, the "picking"and "shifting" steps occur repeatedly in the formation of each of thefirst, third, fifth and subsequent odd patterns formed by the palletizer10.

With particular reference to FIG. 5 and as described above, the firstpattern includes a front row containing 9 (n-1) containers indicated byC₁, and a last row of 9 (n-1) containers identified by C₁. The nextforwardmost row not part of the first pattern includes 10 (n)containers, 9 of which are identified as C₃ and 1 of which is identifiedas container CX. The row of containers positioned immediately upstreamof the row comprising containers C₃ and CX includes 9 (n-1) containersidentified by C₂.

With particular reference to FIG. 6, the second pattern formed by thepalletizer assembly 10 is shown. Containers C₂ comprising the front rowhave passed container CX by the slide by step such that container CXoccupies a position in the second row of the second pattern. The lastrow of the second pattern is also comprised of 9 (n-1) containersidentified by C₂. FIG. 6 also shows the next most forward row ofcontainers, which are identified as C_(3A), which total 10 (n)containers, and which become the second row of containers in the thirdpattern in the manner described below.

With particular reference to FIG. 7, which illustrates the third patternbeing formed by the palletizer assembly 10, the containers C₃ that wereremoved from between the last row of containers C₁ in the first patternand the front row of containers C₂ in the second pattern are insertedinto the stream as a row immediately in advance of the row of 10 (n)containers C_(3A), and are shifted in unison into position to occupy the9 (n-1) lines that are filled by a row serving as a front row or lastrow in a pattern.

After the containers C₃ are repositioned into the stream as the frontrow of the third pattern, the next row of 10 containers C_(3A) advancesand fills in behind the front row of containers C₃. The last row ofcontainers in the third pattern are shown in FIG. 7 as containers C₃ andas crossing the outline of a pallet P, and are shown in FIG. 8 asoccupying the last row of the third pattern. The third patternillustrated by FIG. 8 is identical to the first pattern shown in FIG. 5and the second pattern shown in FIG. 6, and the above described processis repeated with respect to the formation of the fourth, fifth, etc. . .. patterns.

The construction and operation of the palletizer 10 and sweep assembly22 to carry out this repeated arrangement and rearrangement of thecontainers C is set forth below.

Referring now to FIGS. 3 and 4, the sweep assembly 22 includes a frame70 having a pair of generally parallel side members 72 positioned onopposite sides of the conveyor assembly side rails 17. The side members72 are supported by roller assemblies (not shown) for reciprocalmovement relative to the conveyor support surface 16 along a pair ofsweep assembly support rails 74. The sweep assembly 22 is reciprocatedbetween a upstream or "retreat" position (Shown in FIG. 9) wherein thesweep assembly is located adjacent the main hoist 26 and an advanced ordownstream position (Shown in FIGS. 14 and 15) wherein the sweepassembly 22 is located over the main hoist 26 by means of a belt drive75 shown in FIGS. 3 and 4.

The frame 70 also includes a cross member 76 extending between the sidemembers 72. The cross member 76 extend generally perpendicular to thedirection of travel of the containers C and are located above thecontainer supporting surface 16 (shown in phantom in FIG. 3).

As best shown in FIG. 3, the sweep assembly 22 also includes a pair offorward or downstream stanchions 78 that extend vertically upward fromrespective side members 72. The sweep assembly 22 also includes a pairof rearward stanchions 80 extending vertically upward from the upstreamends of the side members 72. Each of the pairs of stanchions 78, 80include a generally vertically extending slide 82 having a lower endconnected to a side member 72 and in upper end supported by the upperend of the associated stanchion 78,80.

The sweep assembly 22 also includes a forward plunger assembly 84 whichextends across the container support surface 16 between the side members72 and adjacent the forward cross member 76. The sweep assembly 22 alsoincludes a rearward plunger assembly 86 located at the upstream end ofthe frame 70 and extending between the side members 72.

The forward plunger assembly 84 and rearward plunger assembly 86 aresimilarly constructed and operate in a similar manner. Accordingly, onlythe rear plunger assembly 86 will be described in detail. With referenceto FIGS. 9-11, the rear plunger assembly 86 includes a plunger support88 having opposite ends slidably supported at its opposite ends by therespective slides 82 on the rearward stanchions 80. The plunger support88 is slidable along the slides 82 between a lowered position (shown inFIGS. 9 and 10) and a raised position (shown in FIGS. 17, 19 and 25).

The rear plunger assembly 86 also includes a plurality of cylindrical,finger-like plungers 90 which are fixed to, and extend downwardly from,the plunger support 88 toward the container support surface 16. As bestshown in FIG. 10, each of the plungers 90 has a distal end 92 that, whenthe plunger support 88 is lowered, is spaced from the container supportsurface, 16 and have a diameter appropriately sized to be received bythe interior of a container C.

As shown in FIG. 4 and in FIG. 11, the plungers 90 are arranged in astaggered pattern extending along the length of the plunger support 88such that the center line of each plunger 90 will be centered over theinterior space of a container C. In this regard, in the illustratedembodiment, the rear plunger assembly 86 includes a total of nineteenplungers 90, ten of which are positioned relatively downstream and 9 ofwhich are positioned relatively upstream. The positions of the plungers90 across the plunger support 88 are spaced apart approximately 1/2 of acontainer diameter and are centered on the center lines of containers Cpassing along the container support surface 16. Thus, as the stream ofcontainers C passes under the plunger support 88, the plungers 90 can beregistered with individual containers. Even more particularly, thedownstream plungers 90 are engageable with a row of 10 (n) containers,and the upstream plungers 90 are registerable and engageable with thecontainers in a row of 9 (n-1) containers.

The rear plunger assembly 86 also includes means for selectively andrepeatedly moving the plunger support 88 between the lowered positionand the raised position. While various suitable alternative arrangementscould be used, in the illustrated embodiment, the rear plunger assembly86 includes a pair of rear plunger assembly lift actuators 100 on therearward stanchions 80 and adjacent the slides 82.

As mentioned above, the forward plunger assembly 84 is constructed andoperates in a manner similar to the rearward plunger assembly 86,including the provision of a staggered row of plungers 90 extendingacross the container support surface 16 and the ability to move betweena lowered position and an upper position by virtue of selectiveactuation of an actuator.

As thus far described, therefore, the sweep assembly 22 is movable intwo respects: first, the sweep assembly 22 is movable between theretreated position wherein the frame 70 is located adjacent the mainhoist 26 and wherein the forward and rearward plunger assemblies 84, 86defined therebetween a staging area in which a series of rows ofcontainers C are formed into a pattern to be transferred to the mainhoist 26, and an advanced position wherein the frame 70 is moved overthe main hoist 26 into registry with a pallet P supported by the mainhoist 26. When the sweep assembly 22 is in the advanced position, theforward and rearward plunger assemblies 84, 86 are located over thepallet P.

The sweep assembly 22 is also movable between a lowered position whereinthe plunger support 88 is lowered, and the forward and rearward plungerassemblies 84, 86 are positioned so that the distal ends 92 of theplungers 90 are in closely spaced relation to the container supportsurface 16. The sweep assembly 22 can also be moved into a raisedposition wherein the plunger support 88 is raised along the slides 82.When the plunger support 88 is raised, the forward and rearward plungerassemblies 84, 86 are also raised from the container support surface 16so that the distal ends 92 of the plungers 90 are positioned above theplane defined by the uppermost extent of the containers C advancingalong the container support surface 16.

The sweep assembly 22 also includes (FIGS. 9 and 10) a container shiftassembly 120 that is supported by the frame 70 adjacent the rearwardplunger assembly 86. The container shift assembly 120 includes a pair ofshifter slide rails 124 extending rearwardly or upstream from respectiveends of the rearward plunger support 88. As shown in FIGS. 9 and 10, thedownstream ends 126 of the shifter slide rails 124 are located adjacentand supported by the ends of the rearward plunger support 88 and,therefore, are raised and lowered with the rearward plunger assembly 86.The upstream ends 128 of the shifter slide rails 124 are offsetapproximately 1/2 of a container diameter in a direction perpendicularto the direction of travel of the containers C such that the shifterslide rails 124 are parallel and extend upstream from the shiftersupport bar 122 at an angle with respect to the direction of travel. Asingle end 128 of a slide rail 124 is shown in FIG. 10. Consequently,the offset between the downstream and upstream ends 126, 128 of theshifter slide rail 124 is equal to the distance between the center linesof adjacent lines of containers C. The shifter slide rails 124 eachinclude a track 130 (shown in FIG. 10) extending between the ends 126,128 of the shifter slide rail 124, and each slide rail 124 extendsgenerally horizontally.

The container shift assembly 120 also includes (FIGS. 9-11) a vacuumfitting assembly 132 which is supported by the shifter slide rails 124for movement relative to the rear plunger assembly 86. Moreparticularly, the vacuum fitting assembly 132 includes a cross bar 134having opposite ends (one shown in FIG. 10) supported by a respectiveshifter slide rail 124.

The vacuum fitting assembly 132 also includes (FIG. 10) a pair ofjournal assemblies 136 located respectively at each end of the cross bar134 and supporting the cross bar 134 for sliding movement along theshifter slide rails 124. In this regard, each journal assembly 136cooperates with the elongated track 130 in the shifter slide rail 124 topermit movement, by means of actuator 125 connected to the rearwardplunger assembly support 88 and the cross bar 134, of the cross bar 134between (FIG. 13) a first or pickup position located adjacent thedownstream ends 126 of the rails 124 and the rearward plunger assembly86 and (FIG. 11) a second or drop off position wherein the cross bar 134is moved along the rails 124 toward the upstream end 128 and is extendedaway from the rearward plunger assembly 86.

The vacuum fitting assembly 132 also includes a vacuum fitting plate 138that is supported by the cross bar 134 and that extends between therails 124. The vacuum fitting plate 138 is generally located below thecross bar 134 and, for reasons explained below, is supported by thecross bar 134 for pivotal movement relative thereto.

The vacuum fitting assembly 132 also includes a plurality offinger-like, generally cylindrical vacuum fittings 140 extending in asingle line across the length of the vacuum fitting plate 134. Thevacuum fittings are connected to a vacuum (not shown) for liftingcontainers C in which the vacuum fittings 140 are housed. The vacuumfittings 140 are spaced apart such that the center line of adjacentvacuum fittings 140 are spaced apart by a distance of a containerdiameter. In the illustrated embodiment, therefore, the vacuum fittingassembly 132 includes 9 (n-1) such vacuum fittings 140. However, it willbe readily understood that the vacuum fitting assembly 132 requires atotal of n-1 fittings 140 wherein n equals the greatest number ofcontainers in any row of containers C formed by the palletizer 10.

As mentioned above, the vacuum fitting plate 138 is supported by thecross bar 134 for pivotal movement relative thereto between a first or"down" position wherein the vacuum fittings 140 extend generallyvertically and are closely spaced to the container support surface 16when the container sweep assembly is in the lowered position, and asecond or up position wherein the vacuum fittings 140 extend generallyhorizontally and point rearwardly or upstream of the vacuum fittingplate 134.

The container shift assembly 120 also includes a vacuum fitting fixtureactuator 142 connected to the vacuum fitting plate 138 for selectivelypivoting the vacuum fitting plate 138 between the down position and theup position.

When the vacuum fitting assembly 132 is pivoted into the down positionand the vacuum fitting plate 134 is retracted into the pickup positionimmediately upstream of the rearward plunger assembly 86, the vacuumfittings 140 are positioned so as to occupy 9 of the 19 lines extendingacross the container support surface 16. More particularly, the 9positions occupied by the vacuum fittings 140 are the 9 positions in arow of 10 containers that are occupied by the containers to be picked upthrough execution of the above-described container shifting process.This position is shown in phantom in FIG. 10.

When the vacuum fitting assembly 132 is extended along the shifter sliderails 124 to the second or drop off position, by virtue of the angledorientation of the slide rails 124, the vacuum fittings 140 are shiftedor move the amount of the offset of the slide rails 124 into an adjacentline of containers C. This offset of the vacuum fittings 140 is alsoshown in FIG. 10. When the vacuum fitting plate 138 is pivoted into thedown position and the cross bar 134 is moved into the extended position,the vacuum fittings 140 register with the plungers 90 in the rearplunger assembly 86 which engage the last row of containers C in apattern of containers (i.e., the plunger 90 in the plunger assembly 86which is second from the left as shown in FIG. 10).

The container sweep assembly 22 is thus moveable in four differentaspects: the sweep assembly 22 can be moved between the advanced andretreated positions, and, with the forward and rearward plungerassemblies 84, 86 can be moved between the lowered and raised positions;the cross bar 134 can be moved between the retracted and extendedpositions; and the vacuum fitting plate 138 can be pivoted between thedown and up positions.

The container sweep 22 operates as follows to rearrange a stream ofcontainers C in a voidless pattern into patterns of containers C havinga front row of n-1 containers and a last row of n-1 containers.Particularly, and with reference to FIG. 12, the operation of thepalletizer assembly 10 will be described with the container sweep 22being in an initialized position wherein the container sweep assembly 22is in the retreat position and is in the lowered position.

When in the initialized position, the container shifter assembly 120 isin the retracted position and the vacuum fitting assembly 132 is pivoteddownward. When so positioned, the container sweep assembly 22 introducesplungers 90 along the forward plunger assembly and along the rearwardplunger assembly 86 into the containers which respectively are the firstand last rows of the first pattern. At this time the vacuum fittings 140in the container shift assembly 120 apply a vacuum to the bottom of therespective containers C in which the vacuum fittings 140 are housed thuspicking up the 9 containers in the row immediate following the lastcontainers of the first pattern.

Next, as shown in FIGS. 14 and 15, the container sweep apparatus 22moves forward toward the advanced position. The first pattern ofcontainers also advances by virtue of engagement of the forward andrearward plunger assemblies 84, 86 with the first and last rows ofcontainers. The container sweep assembly 22 moves forward at a ratesufficiently faster than the rate of advance of the containers C leftbehind by the container sweep assembly 22 such that a gap or clearancebetween the container shift assembly 120 and the leading edge of theadvancing stream of containers is sufficient for the vacuum fittingplate 138 and the associated fittings 140 and containers C supported onthe fittings can pivot from the down position to the horizontal, upposition. It should be noted that during the advance of the containersweep assembly 22 transferring the first pattern into the main hoistthat the container shift assembly 120 cross bar 134 remains in theretracted position.

Next, as illustrated in FIGS. 16 and 17, the container sweep assembly 22moves into the raised position such that the distal ends 92 of theplungers 90 in the forward plunger assembly 84 and the rearward plungerassembly 86 retract from the containers to a position above a planedefined by the uppermost extent of the containers. The container shiftassembly 120 remains in the retracted position and the vacuum fittingassembly remains pivoted in the up position. Also, the containersconstituting the second pattern move into the sweep area and engage thepattern formers 28 at the forward edge of the sweep area.

Next, as shown in FIGS. 18 and 19, the container sweep assembly 22remains in the raised position and moves upstream relative to thecontainers to the retreated position. Again, the container shiftassembly 120 remains retracted and the vacuum fitting plate 138 remainspivoted up. In the retreated position, the plungers 90 in the forwardand rearward plunger assemblies 84, 86 register over the containers inthe front row and the last row of the second pattern.

As best shown in FIG. 4, the 9 containers removed from the stream ofcontainers by the container shift assembly 120 remain on the vacuumfittings 140 in a position pivoted upwardly above the stream ofcontainers. The 10th container, which is left behind by the containershift assembly 120, contacts the pattern former 28 first, i.e., leadsthe advancing stream of containers to the pattern former and reaches itsposition in the second row of the first pattern. Subsequently, theremainder of the containers C slide by this container that was leftbehind by the container shift assembly 120 so that the second patternforms behind the pattern stops 28.

Next, as best shown in FIGS. 20 and 21, the container sweep assembly 22moves into the lower position and the plungers 90 in the forward andrearward plunger assemblies 84, 86 move into a housed relation to thecontainers C in the front row and last row of the second pattern. Thecontainer shift assembly 120 remains retracted and the vacuum fittingassembly 132 remains pivoted up so that movement of the container sweepassembly 22 into the lower position and registration of the plungers 90in the containers is not prevented by any interference of the containershift assembly 120 with the containers on the container support surface16.

Subsequently, as best shown in FIGS. 22-23, the container sweep assembly22 advances the second pattern, thereby creating a clearance between thelast row of the second pattern and the leading edge of the advancingcontainers. When the gap between the last row of the second pattern andthe leading edge of the advancing containers is sufficiently great, thecontainer shift assembly 120 operates to pivot the vacuum fittingassembly 132 from the up position to the down position, i.e., so thatthe 9 containers supported by the vacuum fittings 140 move into avertical position closely spaced to the container support surface 16.During this pivoting movement of the vacuum fitting assembly 132, thecross bar 134 on the container shift assembly 120 moves along theshifter slide rails 124 toward the extended position at such a rate thatwhen the container sweep assembly 22 reaches the fully advanced positionas shown in FIG. 23, the containers on the vacuum fitting assemblies 140are precisely placed in the pattern stop 28 in the positions to beoccupied by the first row of the third pattern of containers. As shownin FIG. 22, this placement occurs immediately behind the pattern stops28 and before the advancing stream of containers arrives at the patternstops 28. The vacuum fittings 140 then release the containers inposition at the pattern stop 28. Thus, the 9 cans removed from thestream of containers by the container shifting apparatus are reinsertedin position to become the first row of containers in the third pattern.

Subsequently, and as shown in FIGS. 24 and 25, the container sweepassembly 22 moves into the raised position, the container sweep assembly22 moves upstream to the retreated position, the container shiftassembly 120 moves to the retracted position and the vacuum fittings 140remain in the pivoted down position.

The container sweep assembly 22 is thus poised to move back into theinitialized position and to sweep the third pattern into the main hoist.

Various features of the invention are set forth in the following claims.

What is claimed is:
 1. A palletizer comprising:a conveyor assembly forconducting a plurality of containers, a pattern former for arranging thecontainers into a voidless pattern, and a container sweep assembly forrepeatedly segregating the containers into a series of predeterminedpatterns and for transferring the patterns onto a pallet, the containersweep assembly including a frame movable between one and anotherpositions relative to said pattern former, a forward plunger assemblysupported by the frame and defining a first row of containers in thepattern, a rearward plunger assembly supported by the frame and defininga last row of containers in the pattern, said forward and said rearwardplunger assemblies being movable with said frame between said one andanother positions, and a vacuum fitting assembly attached to the frameof the container sweep assembly, said vacuum fitting assembly beingadapted to engage a row of containers not positioned within the patternof containers for movement relative to the frame of the sweep assemblybetween a retracted position adjacent the rearward plunger assembly andan extended position spaced away from the rearward plunger assembly. 2.A method of forming a series of predetermined patterns of cylindricalarticles, said method comprising the steps of:providing a stream ofcontainers, providing a sweep assembly controllably movable relative tosaid stream of containers between one and another positions, arrangingthe stream of containers into a voidless pattern having alternating rowsdefined respectively by including n containers and n-1 containers,segregating a first pattern of containers having a first row includingn-1 containers and a last row of n-1 containers using said sweepassembly that removes the first pattern of containers from the stream ofcontainers and places the first pattern onto a pallet, removing n-1containers from the next row of containers not part of the firstpattern, segregating a second pattern of containers having a first rowincluding n-1 containers and a last row of n-1 containers using thesweep assembly to remove the second pattern of containers from thestream of containers and place the second pattern onto the pallet, andsegregating a third pattern of containers, including the step of placingthe temporarily removed containers into a row of n-1 containers in thethird pattern using said sweep assembly to remove the third pattern ofcontainers from the stream of containers and place the third patternonto the pallet.
 3. A method of forming a series of predeterminedpatterns of cylindrical articles as claimed in claim 2 wherein the n-1containers are removed from a row of n containers in the step ofremoving n-1 containers.
 4. A palletizer assembly comprisinga sweepassembly including a frame having a pair of generally parallel sidemembers and a cross member extending between the side members, the sidemembers having upstream ends and downstream ends and the sweep assemblyalso including a pair of forward stanchions that extend verticallyupward from the downstream ends of the respective side members, and apair of rearward stanchions extending vertically upward from theupstream ends of the side members, a pair of generally verticallyextending slides, each of the slides having a lower end connected to aside member and an upper end, a forward plunger assembly extendingacross between the side members, a rearward plunger assembly extendingbetween the side members, each of said plunger assemblies including aplunger support slidably supported by a respective slide between alowered position and a raised position, each plunger assembly includinga plurality of fingers which are fixed to, and extend downwardly from,the respective plunger support, and a container shift assembly supportedby the frame and including a pair of shifter slide rails extendingrearwardly of the rearward plunger support, the shifter slide railshaving upstream ends and downstream ends, the upstream ends of theshifter slide rails being offset from the downstream ends of the sliderrails.
 5. A method of forming a series of predetermined patterns ofcylindrical articles as claimed in claim 2 wherein the row of n-1containers is placed into a first row in the third pattern in the stepof placing the temporarily removed containers into a row of n-1containers in the third pattern.
 6. A method of forming a series ofpredetermined patterns of cylindrical articles as claimed in claim 2,wherein the step of providing a stream of containers is done using aconveyor.
 7. A method of forming a series of predetermined patterns ofcylindrical articles as claimed in claim 2 wherein the step of arrangingthe stream of containers into a voidless pattern having alternating rowsincluding n containers and n-1 containers is done using pattern stopsthat are arranged to correspond with a staggered lead edge of thecontainers.
 8. A method of forming a series of predetermined patterns ofcylindrical articles as claimed in claim 2 wherein said step ofsegregating a first pattern of containers is done using a sweepassembly.
 9. A method of forming a series of predetermined patterns ofcylindrical articles as claimed in claim 8 wherein said step ofsegregating a second pattern of containers is done using the sweepassembly.
 10. A method of forming a series of predetermined patterns ofcylindrical articles as claimed in claim 9 wherein said step ofsegregating a third pattern of containers is done using the sweepassembly.
 11. A method of forming a series of predetermined patterns ofcylindrical articles as claimed in claim 2 wherein of removing n-1containers from the first pattern is done using a container shiftassembly.
 12. A method of forming a series of predetermined patterns ofcylindrical articles as claimed in claim 2 wherein said step of placingthe removed containers into a row of n-1 containers in the third patternfurther includes the step of offsetting the temporarily removedcontainers by a distance equal to one-half a container diameter.
 13. Amethod of forming a series of predetermined patterns of cylindricalarticles as claimed in claim 12 wherein the step of placing thetemporarily removed containers into a row of n-1 containers in the thirdpattern is done using a container shift assembly.
 14. A palletizerassembly as claimed in claim 4 further comprising a conveyor assemblyfor conveying articles onto a pallet, the conveyor assembly extendingintermediate the pair of generally parallel side members.
 15. Thepalletizer assembly as claimed in claim 14 wherein the conveyor assemblyincludes a container support surface and further comprising a pluralityof selectively retractable pattern stops which extend upwardly throughthe container support surface.
 16. The palletizer assembly as claimed inclaim 4 wherein the plungers in one of the forward plunger assembly andthe rearward plunger assembly is arranged in a staggered patternextending along the respective plunger supports.
 17. The palletizerassembly as claimed in claim 4 wherein each of the plurality of fingerson the forward plunger assembly and the rearward plunger assemblyinclude a distal end having a diameter that is appropriately sized to bereceived by the interior of a container.
 18. The palletizer assembly asclaimed in claim 4 wherein the rearward plunger assembly and the forwardplunger assembly each include means for selectively and repeatedlymoving the plunger support between a lowered position and a raisedposition.
 19. The palletizer assembly of claim 18 wherein the means forselectively and repeatedly moving the plunger support includes a pair ofrearward plunger assembly lift actuators positioned on the rearwardstanchions and a pair of forward plunger assembly lift actuatorspositioned on the forward stanchions.
 20. The palletizer assembly ofclaim 4 wherein the upstream ends and the downstream ends of the shifterslide rails are offset a distance that is equal to one half a diameterof the containers.
 21. The palletizer assembly as claimed in claim 4wherein the shifter slide rails each include a track extending betweenthe upstream ends and the downstream ends of the shifter slide rails.22. The palletizer assembly of claim 4 wherein the downstream ends ofthe shifter slide rails are attached to the rearward plunger support.23. The palletizer assembly as claimed in claim 4 wherein the containershift assembly further includes a vacuum fitting assembly supported bythe shifter slide rails.
 24. The palletizer assembly as claimed in claim23 wherein the vacuum fitting assembly includes a cross bar havingopposite ends supported by each of the shifter slide rails.
 25. Thepalletizer assembly as claimed in claim 23 wherein the vacuum fittingassembly includes a plurality of finger-like vacuum fittings that areadapted to extend into a row of containers.